Reaction device and reaction method for gas-solid double-circulation pulverized coal pyrolysis

Abstract

The invention relates to a reaction device and a reaction method for gas-solid double-circulation pulverized coal pyrolysis. The reaction device comprises an ascending reactor, a settler, a continuous oxidation self-heating ascending tube reactor, an oxidant preheater, a heat carrier heater, a feeding unit, a gas-solid separation unit, an oil-gas separation unit and a circulating coal gas pipeline, an inlet end of the upstream reactor is connected with a bottom heat carrier outlet of the heat carrier heater, a pulverized coal outlet of the feeding unit and an outlet of the circulating coal gas pipeline, and an outlet end is positioned in the settler; a bottom coke breeze outlet of the settler and an outlet of the oxidant preheater are connected with the continuous oxidation self-heating ascending tube reactor, and an outlet end of the continuous oxidation self-heating ascending tube reactor is connected with a top inlet of the heat carrier heater; and a bottom coke breeze outlet of the settler is connected with a bottom inlet of the heat carrier heater through a circulating inclined pipe. The reaction device provided by the invention can realize equipment miniaturization, temperature control precision and operation stabilization, and improves the charking efficiency.

Description

Technical Field

[0001] This invention relates to the field of coal chemical technology, specifically to a gas-solid dual-circulation pulverized coal pyrolysis reaction apparatus and reaction method. Background Technology

[0002] With increasing energy demand and stricter environmental protection requirements, the efficient and clean conversion of low-rank pulverized coal is a key research focus in the coal chemical industry. Pulverized coal pyrolysis is an effective technology for converting low-rank coal, and it has already achieved million-ton-scale plant operation, showing promising application prospects.

[0003] However, two major technical bottlenecks still exist in the field of pulverized coal pyrolysis. First, the coal-fired heating system urgently needs optimization. Due to the low operating pressure of pulverized coal pyrolysis, the heat carrier heater needs to simultaneously meet core functions such as coke feed distribution, oxidant supply and mixing combustion, heat carrier mixing and heating, gas-solid two-phase separation, and combustion exhaust gas emission. To achieve the coordinated realization of these functions, the heat carrier heater needs to reserve a large amount of redundant space, including space for coke and oxidant mixing, gas-solid separation buffer space, heat carrier temperature equalization and storage space, and operation and maintenance space, to ensure that each functional area does not interfere with each other. This necessitates the use of a large-volume, large-diameter design for the heat carrier heater, resulting in a significant increase in equipment footprint and overall size, and higher investment costs. Second, the heat carrier heater has limited operational flexibility. Heat carrier heaters typically employ a turbulent bed design. When the load changes, the oxidant flow rate also changes accordingly. If the flow rate decreases after the change, it will cause uneven temperature distribution and local overheating. Therefore, the lack of operational flexibility limits the adaptability of the heat carrier heater under different operating conditions.

[0004] Therefore, given the aforementioned technical bottlenecks, how to achieve equipment miniaturization, precise temperature control, and stable operation is a technical problem that needs to be solved. Summary of the Invention

[0005] To address the above problems, the present invention aims to provide a reaction apparatus and reaction method for gas-solid dual-circulation pulverized coal pyrolysis.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a reaction device for gas-solid dual-circulation pulverized coal pyrolysis, the reaction device comprising an upward reactor, a settling tank, a continuous oxidation self-heating upward tube reactor, an oxidant preheater, a heat carrier heater, a feeding unit, a gas-solid separation unit, an oil-gas separation unit, and a circulating gas pipeline. The inlet of the upward reactor is connected to the bottom heat carrier outlet of the heat carrier heater, the pulverized coal outlet of the feeding unit, and the outlet of the circulating gas pipeline, respectively. The outlet end of the upward reactor is located inside the settling tank; The bottom coke outlet of the settling tank and the outlet of the oxidant preheater are respectively connected to the inlet end of the continuous oxidation self-heating upward tube reactor, and the outlet end of the continuous oxidation self-heating upward tube reactor is connected to the top inlet of the heat carrier heater. The bottom coke outlet of the settling device is connected to the bottom inlet of the heat carrier heater via a circulating inclined tube; The top gas phase outlet of the settling device is connected in sequence to the gas-solid separation unit and the oil-gas separation unit.

[0007] The reaction apparatus provided by this invention employs a closed-loop system comprising a settling tank, a heat carrier heater, an upward reactor, and a continuous oxidation self-heating upward tube reactor. The settling tank is typically located above the heat carrier heater, and the coke powder at the bottom of the settling tank is transported to the heat carrier heater via a circulating inclined tube. This invention specifically designs the continuous oxidation self-heating upward tube reactor and positions it between the bottom of the settling tank and the top of the heat carrier heater, enabling integrated coke pre-calcination, enhanced fluidization, and directional conveying, thereby improving the efficiency of coke combustion.

[0008] The continuous oxidation self-heating upward-flowing tube reactor and the heat carrier heater provided by this invention work synergistically to form the core unit for pulverized coke combustion. On one hand, the gas-solid two-phase system in the continuous oxidation self-heating upward-flowing tube reactor is in a rapid fluidization state, enhancing gas-solid mass and heat transfer, improving the combustion efficiency of pulverized coke and the heating efficiency of the heat carrier, achieving equal heating in a smaller cavity volume, and realizing the preparation of high-temperature pulverized coke, thus reducing the size and footprint of the heat carrier heater. On the other hand, the continuous oxidation self-heating upward-flowing tube reactor can independently undertake the combustion heating function, working synergistically with the heat carrier heater to achieve precise temperature control and avoid interference from the multi-functional coupling of the heat carrier heater. Furthermore, by setting up the continuous oxidation self-heating upward-flowing tube reactor, the circulation and allocation of the heat carrier can be more flexible. By adjusting the circulation rate of the heat carrier within the continuous oxidation self-heating upward-flowing tube reactor, the energy demand of the pulverized coal pyrolysis reaction can be quickly responded to, improving the flexibility and stability of temperature control and reducing the risk of local overheating and coking.

[0009] Preferably, the upward reactor includes a first straight section, a curved section, and a second straight section along the gas flow direction, wherein the curved section has a bending angle of 90°.

[0010] In this invention, the inlet end of the first straight pipe is the inlet end of the upward reactor, and the outlet end of the second straight pipe is the outlet end of the upward reactor.

[0011] Preferably, the continuous oxidation self-heating upward pipe reactor includes a first horizontal section, a first curved section, a vertical section, a second curved section, and a second horizontal section along the gas flow direction, wherein the curvature angle of the first curved section and the second curved section is 90°.

[0012] In this invention, the inlet end of the first horizontal section is the inlet end of the continuous oxidation self-heating upward tube reactor, and the outlet end of the second horizontal section is the outlet end of the continuous oxidation self-heating upward tube reactor.

[0013] Preferably, the aspect ratio of the vertical segment is (20-50):1, for example, it can be 20:1, 25:1, 30:1, 35:1, 40:1, 45:1 or 50:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] In this invention, by optimizing the length-to-diameter ratio of the vertical section, the gas-solid two-phase fluidization state can be further promoted, enhancing gas-solid mass and heat transfer, and improving the combustion efficiency of pulverized coke and the heating efficiency of the heat carrier. The heat and mass transfer efficiency in the continuous oxidation self-heating upward tube reactor is higher than that of the heat carrier heater. Under the same char-burning load, the continuous oxidation self-heating upward tube reactor has a higher heat load per unit volume, requiring only a smaller cavity volume to complete the heating of the same mass of heat carrier, reducing the volume of the heat carrier heater. The continuous oxidation self-heating upward tube reactor can adjust the circulation rate of the heat carrier, quickly respond to changes in the heat demand of pulverized coal pyrolysis, has low control lag, strong anti-interference ability, keeps the temperature fluctuation of the high-temperature heat carrier within ±2℃, and has high operational flexibility.

[0015] In this invention, the aspect ratio of the vertical segment is the ratio of the length to the inner diameter. When the aspect ratio is constant, the length and inner diameter can be selected as needed. Generally, the length is 10-60m and the inner diameter is 0.4-1.5m.

[0016] Preferably, the continuous oxidation self-heating upward tube reactor has an empty tube structure.

[0017] Preferably, the oxidant preheater is provided with a first oxidant inlet.

[0018] In this invention, the oxidant is introduced into the oxidant preheater through the first oxidant inlet for preheating, and the oxidant includes air or oxygen-rich air.

[0019] Preferably, the bottom of the settling device is provided with a coke product outlet.

[0020] In this invention, a portion of the coke powder collected at the bottom of the settling tank enters a continuous oxidation self-heating upward-flowing tube reactor to prepare high-temperature coke powder (which is also a high-temperature heat carrier), another portion enters a heat carrier heater to prepare a high-temperature heat carrier, and the remaining portion is produced through the coke powder product outlet. The coke powder splitting ratio can be adjusted as needed, which is beneficial to achieving a synergistic process system of high-efficiency charcoal burning, precise temperature control, stable conveying, and high-quality products.

[0021] Preferably, the heat carrier heater is provided with a second oxidant inlet.

[0022] In this invention, the oxidant is fed into the heat carrier heater through the second oxidant inlet. The heat carrier heater further reacts the oxidant and pulverized coke to obtain a high-temperature heat carrier, which is used for pyrolysis of pulverized coal.

[0023] Preferably, a heat carrier heating temperature controller is provided on the outside of the heat carrier heater.

[0024] Preferably, the heat source inlet of the heat carrier heating temperature controller is connected to the bottom heat carrier outlet of the heat carrier heater.

[0025] Preferably, the heat source outlet of the heat carrier heating temperature controller is connected to the bottom inlet of the heat carrier heater via a heat carrier circulation pipeline.

[0026] Preferably, the heat carrier circulation pipeline is further provided with an air inlet so that the gas transported by the heat carrier circulation pipeline is air.

[0027] In this invention, by preferably configuring the heat carrier heater temperature controller, using deoxygenated water as the heat extraction medium, it can be bypassed and arranged outside the heat carrier heater, and the heat carrier can be returned through the heat carrier circulation pipeline. The heat carrier heater temperature controller adopts an intermittent heat exchange mode. The high-temperature heat carrier flows out from the heat carrier heater and enters the heat source side of the heat carrier heater temperature controller, where it exchanges heat with the heat extraction medium inside the heat carrier heater temperature controller to generate medium-pressure steam. The heat extraction load can be flexibly adjusted within the range of 0-100%, and the temperature control accuracy reaches ±2℃. The heat carrier after heat exchange is transported back to the heat carrier heater by air.

[0028] In this invention, the heat carrier heating temperature controller can, on the one hand, regulate the temperature of the high-temperature heat carrier, remove excess heat generated by charcoal burning, and prevent problems such as heat carrier sintering, equipment material wear, and excessive coking due to pulverized coal pyrolysis caused by overheating in the heat carrier heater, ensuring stable operation of the device within a superior temperature range over a long period. On the other hand, it can improve energy utilization efficiency, as the waste heat recovered by the heat carrier heating temperature controller can be converted into secondary energy sources such as steam for process heating and power generation. On the other hand, it can increase the flexibility of system operation. When the type of raw material pulverized coal changes or the processing load fluctuates, the heat carrier heating temperature controller can quickly adjust the amount of heat removed, working with the heat carrier heater to achieve thermal balance without significantly adjusting core process parameters, thus improving the device's adaptability to changes in operating conditions. In addition, when the device is operating at low load, the heat carrier heating temperature controller continues to run, which can increase the amount of oxidant used in the heat carrier heater.

[0029] Preferably, the reaction apparatus further includes a waste heat recovery unit.

[0030] Preferably, the top gas phase outlet of the oil-gas separation unit is connected to the circulating gas pipeline via the cold source side of the waste heat recovery unit.

[0031] Preferably, the top flue gas outlet of the heat carrier heater is connected to the heat source side of the waste heat recovery unit.

[0032] In this invention, the waste heat recovery unit can be a heat exchange device commonly used in the art, including but not limited to waste heat boilers, waste heat exchangers, induced draft fans / blowers, chimneys, etc.

[0033] In this invention, by setting up a waste heat recovery unit, the high-temperature flue gas generated by the heat carrier heater can be used as a heat source to preheat the circulating coal gas, which can improve the energy utilization rate, avoid the influence of the temperature fluctuation of the circulating coal gas on the temperature of the carried materials, and improve the pyrolysis efficiency.

[0034] Preferably, the gas phase outlet of the gas-solid separation unit is connected to the oil-gas separation unit.

[0035] In this invention, the gas-solid separation unit can be a commonly used gas-solid separation device in the art, such as a cyclone separator.

[0036] Preferably, the top gas phase outlet of the oil-gas separation unit is connected to the coal gas product outlet.

[0037] Preferably, the oil-gas separation unit is provided with a coal tar product outlet.

[0038] In this invention, the oil-gas separation unit can be a commonly used oil-gas separation device in the art, including but not limited to cooling towers, heat exchangers, electrostatic precipitators, and circulating gas booster fans.

[0039] In this invention, the feeding unit can be a commonly used feeding device in the art, including but not limited to raw material tanks, lock hoppers, metering feed tanks, and feeding rotary valves. The pulverized coal output by the feeding unit is generally crushed pulverized coal.

[0040] In a second aspect, the present invention provides a reaction method for gas-solid dual-circulation pulverized coal pyrolysis, wherein the reaction method employs the gas-solid dual-circulation pulverized coal pyrolysis reaction apparatus described in the first aspect of the present invention; the reaction method includes the following steps: Pulverized coal and high-temperature heat carrier are transported via circulating coal gas and undergo pyrolysis in an upward reactor to obtain a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in a settling tank, with some of the coke powder settling to the bottom of the settling tank. The remaining gaseous mixed reaction products undergo a second gas-solid separation in a gas-solid separation unit. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in an oil-gas separation unit to obtain circulating coal gas, coal gas products, and coal tar products. Part of the coke powder at the bottom of the settling tank and the preheated oxidant from the oxidant preheater undergo a first combustion reaction in a continuous oxidation self-heating up-tube reactor to obtain high-temperature coke powder, which then enters the heat carrier heater. Part of the coke powder at the bottom of the settling tank, the high-temperature coke powder from the continuous oxidation self-heating upward tube reactor, and the oxidant undergo a second combustion reaction in the heat carrier heater to obtain a high-temperature heat carrier for pyrolysis reaction; The remaining coke produced at the bottom of the settling tank is coke product.

[0041] The reaction method provided by this invention involves a first combustion reaction in a continuous oxidation self-heating updraft reactor and a second combustion reaction in a heat carrier heater. This improves the combustion efficiency of pulverized coke and the heating efficiency of the heat carrier, enabling the preparation of high-temperature pulverized coke while reducing the size and floor space of the heat carrier heater. It also allows for precise temperature control, enhances the flexibility of heat carrier circulation and allocation, and meets the needs of different pulverized coals.

[0042] Preferably, the temperature of the pyrolysis reaction is 450-650℃, for example, it can be 450℃, 500℃, 520℃, 540℃, 560℃, 580℃, 600℃, 620℃, 640℃ or 650℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0043] Preferably, the pyrolysis reaction time is 1-10s, for example, it can be 1s, 2s, 4s, 6s, 8s or 10s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0044] Preferably, the mass ratio of the high-temperature heat carrier to pulverized coal in the pyrolysis reaction is (3-10):1, for example, it can be 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] In this invention, the pyrolysis reaction of pulverized coal is synergistically controlled by circulating coal gas and high-temperature heat carrier (pulverized coke), which can accurately match the physical properties of the heat carrier such as flow rate, particle size and heat capacity, meet the pyrolysis requirements of different types of pulverized coal, and achieve a dynamic balance between the heat supply of the heat carrier and the heat absorption of pulverized coal.

[0046] Preferably, the temperature of the first combustion reaction is 600-950℃, for example, it can be 600℃, 620℃, 640℃, 660℃, 680℃, 700℃, 720℃, 740℃, 760℃, 780℃, 800℃, 820℃, 840℃, 860℃, 880℃, 900℃, 920℃, 940℃ or 950℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0047] Preferably, the temperature of the second combustion reaction is 600-950℃, for example, it can be 600℃, 620℃, 640℃, 660℃, 680℃, 700℃, 720℃, 740℃, 760℃, 780℃, 800℃, 820℃, 840℃, 860℃, 880℃, 900℃, 920℃, 940℃ or 950℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0048] Preferably, the residence time of the pulverized coke in the continuous oxidation self-heating upward tube reactor is 1-10s, for example, it can be 1s, 2s, 4s, 6s, 8s or 10s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0049] Preferably, the oxidant includes air or oxygen-rich air.

[0050] Preferably, the temperature of the preheating oxidant is 200-600℃, for example, it can be 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, 320℃, 340℃, 360℃, 380℃, 400℃, 420℃, 440℃, 460℃, 480℃, 500℃, 520℃, 540℃, 560℃, 580℃ or 600℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0051] Preferably, the flue gas generated by the second combustion reaction is used as a heat source to preheat the circulating coal gas in the waste heat recovery unit, so as to obtain preheated circulating coal gas for conveying materials.

[0052] Preferably, the temperature of the preheated circulating gas is 200-400℃, for example, it can be 200℃, 250℃, 300℃, 350℃ or 400℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0053] Preferably, a portion of the high-temperature heat carrier in the heat carrier heater enters the heat source side of the heat carrier heating temperature controller to heat the heat extraction medium and generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier.

[0054] Preferably, the heat extraction medium includes deoxygenated water.

[0055] Preferably, the load adjustment range of the heat extraction medium is 0-100%, for example, it can be 0%, 10%, 20%, 40%, 60%, 80% or 100%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0056] As a preferred embodiment of the second aspect of the present invention, the reaction method includes the following steps: Pulverized coal from the feeding unit and high-temperature heat carrier from the heat carrier heater are transported by circulating coal gas and pyrolyzed in the upward reactor at a temperature of 450-650℃ for 1-10s. The mass ratio of high-temperature heat carrier to pulverized coal in the pyrolysis reaction is (3-10):1, resulting in a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in a settling tank, with some of the coke powder settling to the bottom of the settling tank. The remaining gaseous mixed reaction products undergo a second gas-solid separation in a gas-solid separation unit. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in an oil-gas separation unit to obtain circulating coal gas, coal gas products, and coal tar products. The coke powder at the bottom of the settling tank and the preheated oxidant (preheated to 200-600°C from the oxidant preheater) undergo a first combustion reaction at 600-950°C in a continuous self-heating up-pipe reactor. The coke powder stays in the continuous self-heating up-pipe reactor for 1-10 seconds, resulting in high-temperature coke powder, which then enters the heat carrier heater. Part of the coke powder at the bottom of the settling tank, high-temperature coke powder from the continuous oxidation self-heating upward tube reactor, and oxidant undergo a second combustion reaction in the heat carrier heater at a temperature of 600-950℃ to obtain a high-temperature heat carrier for pyrolysis reaction; part of the high-temperature heat carrier enters the heat source side of the heat carrier heater temperature controller to heat the heat extraction medium to generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier. The heat extraction medium includes deoxygenated water, and the load adjustment range of the heat extraction medium is 0-100%; the flue gas generated by the heat carrier heater enters the heat source side of the waste heat recovery unit to heat the circulating gas, obtaining preheated circulating gas for material transportation. The remaining coke produced at the bottom of the settling tank is coke product.

[0057] Compared with the prior art, the present invention has the following beneficial effects: (1) The continuous oxidation self-heating upward tube reactor and the heat carrier heater provided by the present invention work together to form the core unit of pulverized coke char production, which can realize the pre-char production of pulverized coke, enhanced fluidization and directional conveying in one, thereby improving the efficiency of char production.

[0058] (2) The continuous oxidation self-heating upward tube reactor provided by this invention features a rapid fluidization state between the gas and solid phases, enhancing gas-solid mass and heat transfer, improving the combustion efficiency of pulverized coke and the heating efficiency of the heat carrier, and achieving equal heating in a smaller cavity volume, thus realizing the preparation of high-temperature pulverized coke. This reduces the size and floor space of the heat carrier heater. Under optimal conditions, the continuous oxidation self-heating upward tube reactor can handle more than 30-80% of the pre-burned char load, reducing the volume of the heat carrier heater by 50-80%, lowering the total equipment investment by 50%, and reducing the floor space by more than 30%.

[0059] (3) The continuous oxidation self-heating upward tube reactor provided by the present invention can independently undertake the combustion and heating function, and work together with the heat carrier heater to achieve precise temperature control and avoid the multi-functional coupling interference of the heat carrier heater.

[0060] (4) The continuous oxidation self-heating upward tube reactor provided by the present invention can make the circulation and allocation of heat carrier more flexible. By adjusting the circulation rate of heat carrier in the continuous oxidation self-heating upward tube reactor, it can quickly respond to the energy demand of pulverized coal pyrolysis reaction, improve the flexibility and stability of temperature control, and reduce the risk of local overheating and coking.

[0061] (5) By setting a heat carrier heating temperature controller on the outside of the continuous oxidation self-heating up-tube reactor, the present invention can control the temperature of the high-temperature heat carrier, remove excess heat generated by burning charcoal, avoid heat carrier sintering, equipment material wear and excessive coking caused by overheating in the heat carrier heater, and ensure that the device operates stably in a better temperature range for a long time; it can improve the energy utilization rate, and the waste heat recovered by the heat carrier heating temperature controller can be converted into secondary energy such as steam for process heating, power generation, etc.; it can also increase the flexibility of system operation. When the type of raw material pulverized coal is changed or the processing load fluctuates, the heat carrier heating temperature controller can quickly adjust the amount of heat removed and achieve thermal balance with the heat carrier heater without significantly adjusting the core process parameters, thus improving the adaptability of the device to changes in operating conditions. In addition, when the device is running at low load, the heat carrier heating temperature controller continues to operate, which can increase the amount of oxidant used in the heat carrier heater. Under optimal conditions, the heat transfer fluid heating temperature controller can keep the temperature fluctuation of the high-temperature heat transfer fluid within ±2℃, thus meeting the stringent requirements for temperature stability in rapid pyrolysis, and the operational flexibility can reach 40-110%. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the reaction apparatus provided in Embodiment 1 of the present invention; Among them, 1-feeding unit; 2-heat carrier heater; 3-upward reactor; 4-sedimentation unit; 5-gas-solid separation unit; 6-oil-gas separation unit; 7-waste heat recovery unit; 8-oxidant preheater; 9-continuous oxidation self-heating upward tube reactor; 10-heat carrier heating temperature controller. Detailed Implementation

[0063] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0064] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0065] Example 1 This embodiment provides a gas-solid dual-circulation pulverized coal pyrolysis reaction device, such as... Figure 1 As shown, the reaction device includes an upward reactor 3, a settling tank 4, a continuous oxidation self-heating upward tube reactor 9, an oxidant preheater 8, a heat carrier heater 2, a feeding unit 1, a gas-solid separation unit 5, an oil-gas separation unit 6, a waste heat recovery unit 7, and a circulating gas pipeline. The inlet end of the upward reactor 3 is connected to the bottom heat carrier outlet of the heat carrier heater 2, the pulverized coal outlet of the feeding unit 1, and the outlet of the circulating gas pipeline. The outlet end of the upward reactor 3 is located inside the settling tank 4. The upward reactor 3 includes a first straight pipe section, a curved section, and a second straight pipe section along the gas flow direction. The bending angle of the curved section is 90°. The oxidant preheater 8 is provided with a first oxidant inlet. The bottom coke outlet of the settler 4 and the outlet of the oxidant preheater 8 are respectively connected to the inlet end of the continuous oxidation self-heating upward tube reactor 9. The outlet end of the continuous oxidation self-heating upward tube reactor 9 is connected to the top inlet of the heat carrier heater 2. The continuous oxidation self-heating upward tube reactor 9 includes a first horizontal section, a first curved section, a vertical section, a second curved section and a second horizontal section along the gas flow direction. The bending angle of the first curved section and the second curved section is 90°. The length-to-diameter ratio of the vertical section is 35:1. The continuous oxidation self-heating upward tube reactor 9 is a hollow tube structure. The bottom coke outlet of the settling device 4 is connected to the bottom inlet of the heat carrier heater 2 via a circulating inclined tube. The bottom of the settling device 4 is also provided with a coke product outlet. The top gas phase outlet of the settling device 4 is connected in sequence to the gas-solid separation unit 5 and the oil-gas separation unit 6. The heat carrier heater 2 is provided with a second oxidant inlet. A heat carrier heating temperature controller 10 is provided on the outside of the heat carrier heater 2. The heat source inlet of the heat carrier heating temperature controller 10 is connected to the bottom heat carrier outlet of the heat carrier heater 2. The heat source outlet of the heat carrier heating temperature controller 10 is connected to the bottom inlet of the heat carrier heater 2 via a heat carrier circulation pipeline. The heat carrier circulation pipeline is also provided with an air inlet so that the conveying gas of the heat carrier circulation pipeline is air. The top flue gas outlet of the heat carrier heater 2 is connected to the heat source side of the waste heat recovery unit 7. The top gas phase outlet of the oil-gas separation unit 6 is connected to the circulating gas pipeline via the cold source side of the waste heat recovery unit 7. The gas phase outlet of the gas-solid separation unit 5 is connected to the oil-gas separation unit 6, the top gas phase outlet of the oil-gas separation unit 6 is connected to the coal gas product outlet, and the oil-gas separation unit 6 is provided with a coal tar product outlet.

[0066] This embodiment also provides a reaction method for gas-solid dual-circulation pulverized coal pyrolysis using the above-mentioned reaction device, the reaction method comprising the following steps: Pulverized coal from feeding unit 1 and high-temperature heat carrier from heat carrier heater 2 are transported by circulating coal gas and pyrolyzed for 10 seconds in upward reactor 3 at a temperature of 600°C. The mass ratio of high-temperature heat carrier to pulverized coal in the pyrolysis reaction is 6:1, resulting in a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in the settling tank 4, with some of the coke powder settling to the bottom of the settling tank 4. The remaining gaseous mixed reaction products undergo a second gas-solid separation in the gas-solid separation unit 5. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in the oil-gas separation unit 6 to obtain circulating coal gas, coal gas products, and coal tar products. The coke powder at the bottom of the settling tank 4 and the preheated oxidant (air) from the oxidant preheater 8, which is preheated to a temperature of 300°C, undergo a first combustion reaction at a temperature of 700°C in the continuous oxidation self-heating upward tube reactor 9. The residence time of the coke powder in the continuous oxidation self-heating upward tube reactor 9 is 6 seconds, resulting in high-temperature coke powder, which then enters the heat carrier heater 2. Part of the coke powder at the bottom of the settling tank 4, the high-temperature coke powder from the continuous oxidation self-heating upward tube reactor 9, and the oxidant undergo a second combustion reaction at a temperature of 700°C in the heat carrier heater 2 to obtain a high-temperature heat carrier for pyrolysis reaction; part of the high-temperature heat carrier enters the heat source side of the heat carrier heater temperature controller 10 to heat the heat extraction medium to generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier. The heat extraction medium is deoxygenated water, and the load adjustment range of the heat extraction medium is 0-100%; the flue gas generated by the heat carrier heater 2 enters the heat source side of the waste heat recovery unit 7 to heat the circulating coal gas, obtaining preheated circulating coal gas for material transportation. The remaining coke produced at the bottom of the settling tank 4 is coke product.

[0067] In this embodiment, the continuous oxidation self-heating upward tube reactor can handle more than 30-80% of the pre-burned carbon load, reducing the volume of the heat carrier heater by 50-80%, the total equipment investment by 50%, and the floor space by more than 30%. Furthermore, in conjunction with the heat carrier heating temperature controller, the temperature fluctuation of the high-temperature heat carrier can be controlled within ±2℃, thus meeting the stringent requirements of rapid pyrolysis for temperature stability, and the operational flexibility can reach 40-110%.

[0068] Example 2 This embodiment provides a gas-solid dual-circulation pulverized coal pyrolysis reaction device, which differs from Embodiment 1 only in that the aspect ratio of the vertical section is 20.

[0069] This embodiment also provides a reaction method for gas-solid dual-cycle pulverized coal pyrolysis using the above-mentioned reaction device. The only difference between this reaction method and Embodiment 1 is that it uses the reaction device provided in this embodiment.

[0070] In this embodiment, the aspect ratio of the vertical section is 20:1. This aspect ratio optimizes the flow and mixing state of pulverized coke and oxidant in the continuous oxidation self-heating upward pipe, which can improve the heating efficiency and heat transfer uniformity, thereby ensuring the temperature stability of the heat carrier and meeting the process requirements of rapid pyrolysis of pulverized coal.

[0071] Example 3 This embodiment provides a gas-solid dual-circulation pulverized coal pyrolysis reaction device, which differs from Embodiment 1 only in that the aspect ratio of the vertical section is 50.

[0072] This embodiment also provides a reaction method for gas-solid dual-cycle pulverized coal pyrolysis using the above-mentioned reaction device. The only difference between this reaction method and Embodiment 1 is that it uses the reaction device provided in this embodiment.

[0073] In this embodiment, the length-to-diameter ratio of the vertical section is 50:1. This length-to-diameter ratio design can extend the residence time of pulverized coke and oxidant in the continuous oxidation self-heating upward pipe, making the contact reaction between the two more complete, thereby further improving the heating rate of the heat carrier and the stability of heat release, and providing a continuous and uniform heat source for pulverized coal pyrolysis.

[0074] Example 4 This embodiment provides a gas-solid dual-circulation pulverized coal pyrolysis reaction device, which differs from Embodiment 1 only in that the aspect ratio of the vertical section is 10.

[0075] This embodiment also provides a reaction method for gas-solid dual-cycle pulverized coal pyrolysis using the above-mentioned reaction device. The only difference between this reaction method and Embodiment 1 is that it uses the reaction device provided in this embodiment.

[0076] In this embodiment, the length-to-diameter ratio of the vertical section is 10:1. This length-to-diameter ratio is too small, resulting in a short residence time of the coke and oxidant in the continuous oxidation self-heating upward pipe. This leads to poor mixing of the coke and oxidant, resulting in incomplete combustion reaction. At the same time, the flow rate is too fast, resulting in uneven heat distribution and local overheating. This leads to low thermal efficiency and insufficient operational flexibility of the equipment.

[0077] Example 5 This embodiment provides a gas-solid dual-circulation pulverized coal pyrolysis reaction device, which differs from Embodiment 1 only in that the aspect ratio of the vertical section is 60.

[0078] This embodiment also provides a reaction method for gas-solid dual-cycle pulverized coal pyrolysis using the above-mentioned reaction device. The only difference between this reaction method and Embodiment 1 is that it uses the reaction device provided in this embodiment.

[0079] In this embodiment, the length-to-diameter ratio of the vertical section is 60:1. This length-to-diameter ratio is too large, resulting in a longer contact time between the coke and the oxidant in the continuous oxidation self-heating upward pipe, which increases system resistance and energy consumption, and raises the risk of coking and blockage. At the same time, an excessively large length-to-diameter ratio will cause a lag in temperature regulation, making it impossible to quickly respond to and adjust the heat output, and will also lead to an increase in equipment size and investment.

[0080] Example 6 This embodiment provides a gas-solid dual-circulation pulverized coal pyrolysis reaction device, which differs from Embodiment 1 only in that it does not include a heat carrier heating temperature controller.

[0081] This embodiment also provides a reaction method for gas-solid dual-cycle pulverized coal pyrolysis using the above-mentioned reaction device. The only difference between this reaction method and Embodiment 1 is that it uses the reaction device provided in this embodiment.

[0082] In this embodiment, the absence of a heat carrier heater temperature controller causes the temperature fluctuation of the heat carrier to increase from ±(1-2)℃ to ±(15-20)℃, which cannot meet the stringent requirements for temperature stability in the rapid pyrolysis of pulverized coal; the operational flexibility also decreases from 40-110% to 70-90%, making it difficult to adapt to process load fluctuations. In addition, in order to ensure the temperature of the heat carrier heater, the flow rate of the oxidant needs to be frequently adjusted, increasing the load on the unit.

[0083] Example 7 This embodiment provides a reaction method for gas-solid dual-circulation pulverized coal pyrolysis. The reaction method uses the reaction apparatus provided in Embodiment 1 and includes the following steps: Pulverized coal from the feeding unit and high-temperature heat carrier from the heat carrier heater are transported by circulating coal gas and pyrolyzed for 10 seconds in the upward reactor at a temperature of 500°C. The mass ratio of high-temperature heat carrier to pulverized coal in the pyrolysis reaction is 3:1, resulting in a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in a settling tank, with some of the coke powder settling to the bottom of the settling tank. The remaining gaseous mixed reaction products undergo a second gas-solid separation in a gas-solid separation unit. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in an oil-gas separation unit to obtain circulating coal gas, coal gas products, and coal tar products. The coke powder at the bottom of the settling tank and the preheated oxidant (air) at 500°C after preheating from the oxidant preheater undergo a first combustion reaction at 600°C in the continuous oxidation self-heating up-pipe reactor. The coke powder stays in the continuous oxidation self-heating up-pipe reactor for 10 seconds, resulting in high-temperature coke powder, which then enters the heat carrier heater. Part of the coke powder at the bottom of the settling tank, high-temperature coke powder from the continuous oxidation self-heating upward tube reactor, and oxidant undergo a second combustion reaction at 600°C in the heat carrier heater to obtain a high-temperature heat carrier for pyrolysis. Part of the high-temperature heat carrier enters the heat source side of the heat carrier heater temperature controller to heat the heat extraction medium to generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier. The heat extraction medium is deoxygenated water, and the load adjustment range of the heat extraction medium is 0-100%. The flue gas generated by the heat carrier heater enters the heat source side of the waste heat recovery unit to heat the circulating gas, obtaining preheated circulating gas for material transportation. The remaining coke produced at the bottom of the settling tank is coke product.

[0084] In this embodiment, the continuous oxidation self-heating upward tube reactor can bear the pre-burned carbon load, reducing the volume of the heat carrier heater by 50-80%, lowering the total investment cost of the equipment, and, in conjunction with the heat carrier heating temperature controller, can control the temperature fluctuation of the high-temperature heat carrier within ±2℃, and the system has high thermal efficiency.

[0085] Example 8 This embodiment provides a reaction method for gas-solid dual-circulation pulverized coal pyrolysis. The reaction method uses the reaction apparatus provided in Embodiment 1 and includes the following steps: Pulverized coal from the feeding unit and high-temperature heat carrier from the heat carrier heater are transported by circulating coal gas and pyrolyzed for 1 second in the upward reactor at a temperature of 650°C. The mass ratio of high-temperature heat carrier to pulverized coal in the pyrolysis reaction is 10:1, resulting in a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in a settling tank, with some of the coke powder settling to the bottom of the settling tank. The remaining gaseous mixed reaction products undergo a second gas-solid separation in a gas-solid separation unit. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in an oil-gas separation unit to obtain circulating coal gas, coal gas products, and coal tar products. Part of the coke powder at the bottom of the settling tank and the preheated oxidant (air) at a temperature of 400°C after preheating from the oxidant preheater undergo a first combustion reaction at a temperature of 850°C in the continuous oxidation self-heating upward tube reactor. The residence time of the coke powder in the continuous oxidation self-heating upward tube reactor is 2 seconds, resulting in high-temperature coke powder, which then enters the heat carrier heater. Part of the coke powder at the bottom of the settling tank, the high-temperature coke powder from the continuous oxidation self-heating upward tube reactor, and the oxidant undergo a second combustion reaction at 850°C in the heat carrier heater to obtain a high-temperature heat carrier for pyrolysis. Part of the high-temperature heat carrier enters the heat source side of the heat carrier heater temperature controller to heat the heat extraction medium to generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier. The heat extraction medium is deoxygenated water, and the load adjustment range of the heat extraction medium is 0-100%. The flue gas generated by the heat carrier heater enters the heat source side of the waste heat recovery unit to heat the circulating gas, obtaining preheated circulating gas for material transportation. The remaining coke produced at the bottom of the settling tank is coke product.

[0086] In this embodiment, the continuous oxidation self-heating upward tube reactor can bear the pre-burned carbon load, reducing the volume of the heat carrier heater by 50-80%, lowering the total investment cost of the equipment, and, in conjunction with the heat carrier heating temperature controller, can control the temperature fluctuation of the high-temperature heat carrier within ±2℃, and the system has high thermal efficiency.

[0087] Comparative Example 1 This comparative example provides a pulverized coal pyrolysis reaction apparatus, which differs from Example 1 only in that it does not include a continuous oxidation self-heating upward tube reactor and an oxidant preheater.

[0088] This comparative example provides a reaction method for pulverized coal pyrolysis using the above-described reaction apparatus. The only difference from Example 1 is the use of the reaction apparatus provided in this comparative example, and the reaction method is adjusted as follows: Pulverized coal from the feeding unit and high-temperature heat carrier from the heat carrier heater are transported by circulating coal gas and pyrolyzed for 10 seconds in the upward reactor at a temperature of 600°C. The mass ratio of high-temperature heat carrier to pulverized coal in the pyrolysis reaction is 6:1, resulting in a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in a settling tank, with some of the coke powder settling to the bottom of the settling tank. The remaining gaseous mixed reaction products undergo a second gas-solid separation in a gas-solid separation unit. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in an oil-gas separation unit to obtain circulating coal gas, coal gas products, and coal tar products. Part of the coke and oxidant at the bottom of the settling tank undergo combustion reaction at 700°C in the heat carrier heater to obtain a high-temperature heat carrier for pyrolysis reaction; part of the high-temperature heat carrier enters the heat source side of the heat carrier heater temperature controller to heat the heat extraction medium to generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier. The heat extraction medium is deoxygenated water, and the load adjustment range of the heat extraction medium is 0-100%; the flue gas generated by the heat carrier heater enters the heat source side of the waste heat recovery unit to heat the circulating gas, obtaining preheated circulating gas for material transportation. The remaining coke produced at the bottom of the settling tank is coke product.

[0089] In this comparative example, a continuous oxidation self-heating up-pipe reactor and an oxidant preheater are not set up. That is, the pulverized coke is directly burned in the heat carrier heater, which increases the required equipment volume of the heat carrier heater and reduces the operational flexibility.

[0090] In summary, the reaction device provided by this invention can achieve miniaturization, precise temperature control, and stable operation, thereby improving charcoal burning efficiency.

[0091] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A gas-solid dual-circulation pulverized coal pyrolysis reaction device, characterized in that, The reaction apparatus includes an upward reactor, a settling tank, a continuous oxidation self-heating upward tube reactor, an oxidant preheater, a heat carrier heater, a feeding unit, a gas-solid separation unit, an oil-gas separation unit, and a circulating gas pipeline. The inlet of the upward reactor is connected to the bottom heat carrier outlet of the heat carrier heater, the pulverized coal outlet of the feeding unit, and the outlet of the circulating gas pipeline, respectively. The outlet end of the upward reactor is located inside the settling tank; The bottom coke outlet of the settling tank and the outlet of the oxidant preheater are respectively connected to the inlet end of the continuous oxidation self-heating upward tube reactor, and the outlet end of the continuous oxidation self-heating upward tube reactor is connected to the top inlet of the heat carrier heater. The bottom coke outlet of the settling device is connected to the bottom inlet of the heat carrier heater via a circulating inclined tube; The top gas phase outlet of the settling device is connected in sequence to the gas-solid separation unit and the oil-gas separation unit.

2. The reaction apparatus according to claim 1, characterized in that, The upward reactor includes a first straight section, a curved section, and a second straight section along the gas flow direction, with the curved section having a bending angle of 90°.

3. The reaction apparatus according to claim 1 or 2, characterized in that, The continuous oxidation self-heating upward pipe reactor includes a first horizontal section, a first curved section, a vertical section, a second curved section, and a second horizontal section along the gas flow direction. The bending angle of the first curved section and the second curved section is 90°. Preferably, the aspect ratio of the vertical segment is (20-50):1; Preferably, the continuous oxidation self-heating upward tube reactor has an empty tube structure.

4. The reaction apparatus according to any one of claims 1-3, characterized in that, The oxidant preheater is provided with a first oxidant inlet; Preferably, the bottom of the settling device is provided with a coke product outlet; Preferably, the heat carrier heater is provided with a second oxidant inlet.

5. The reaction apparatus according to any one of claims 1-4, characterized in that, A heat carrier heating temperature controller is installed on the outside of the heat carrier heater; Preferably, the heat source inlet of the heat carrier heating temperature controller is connected to the bottom heat carrier outlet of the heat carrier heater; Preferably, the heat source outlet of the heat carrier heating temperature controller is connected to the bottom inlet of the heat carrier heater via a heat carrier circulation pipeline; Preferably, the heat carrier circulation pipeline is further provided with an air inlet so that the gas transported by the heat carrier circulation pipeline is air.

6. The reaction apparatus according to any one of claims 1-5, characterized in that, The reaction apparatus also includes a waste heat recovery unit; Preferably, the top gas phase outlet of the oil-gas separation unit is connected to the circulating gas pipeline via the cold source side of the waste heat recovery unit; Preferably, the top flue gas outlet of the heat carrier heater is connected to the heat source side of the waste heat recovery unit.

7. The reaction apparatus according to any one of claims 1-6, characterized in that, The gas phase outlet of the gas-solid separation unit is connected to the oil-gas separation unit; Preferably, the top gas phase outlet of the oil-gas separation unit is connected to the coal gas product outlet; Preferably, the oil-gas separation unit is provided with a coal tar product outlet.

8. A reaction method for gas-solid dual-cycle pulverized coal pyrolysis, characterized in that, The reaction method employs the gas-solid dual-circulation pulverized coal pyrolysis reaction apparatus as described in any one of claims 1-7; the reaction method includes the following steps: Pulverized coal and high-temperature heat carrier are transported via circulating coal gas and undergo pyrolysis in an upward reactor to obtain a mixed reaction product containing coal gas, coal tar and pulverized coke. The mixed reaction products undergo a first gas-solid separation in a settling tank, with some of the coke powder settling to the bottom of the settling tank. The remaining gaseous mixed reaction products undergo a second gas-solid separation in a gas-solid separation unit. The gaseous phase obtained from the second gas-solid separation undergoes oil-gas separation in an oil-gas separation unit to obtain circulating coal gas, coal gas products, and coal tar products. Part of the coke powder at the bottom of the settling tank and the preheated oxidant from the oxidant preheater undergo a first combustion reaction in a continuous oxidation self-heating up-tube reactor to obtain high-temperature coke powder, which then enters the heat carrier heater. Part of the coke powder at the bottom of the settling tank, the high-temperature coke powder from the continuous oxidation self-heating upward tube reactor, and the oxidant undergo a second combustion reaction in the heat carrier heater to obtain a high-temperature heat carrier for pyrolysis reaction; The remaining coke produced at the bottom of the settling tank is coke product.

9. The reaction method according to claim 8, characterized in that, The temperature of the pyrolysis reaction is 450-650℃; Preferably, the pyrolysis reaction takes 1-10 seconds; Preferably, the mass ratio of the high-temperature heat carrier to pulverized coal in the pyrolysis reaction is (3-10):1; Preferably, the temperature of the first combustion reaction is 600-950°C; Preferably, the temperature of the second combustion reaction is 600-950°C; Preferably, the residence time of the pulverized coke in the continuous oxidation self-heating upward tube reactor is 1-10 s; Preferably, the oxidant includes air or oxygen-rich air; Preferably, the temperature of the preheated oxidant is 200-600℃.

10. The reaction method according to claim 8 or 9, characterized in that, The flue gas generated by the second combustion reaction is used as a heat source to preheat the circulating coal gas in the waste heat recovery unit, and the preheated circulating coal gas is used to transport materials. Preferably, the temperature of the preheated circulating gas is 200-400℃; Preferably, a portion of the high-temperature heat carrier in the heat carrier heater enters the heat source side of the heat carrier heating temperature controller to heat the heat extraction medium and generate medium-pressure steam, which is then transported back to the heat carrier heater via air to regulate the temperature of the high-temperature heat carrier. Preferably, the heat extraction medium includes deoxygenated water; Preferably, the load adjustment range of the heat extraction medium is 0-100%.

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